Hydrocarbons and Heterocycles

Alkanes. The saturated open-chain (acyclic) hydrocarbons (Cyd +2) have names ending in -ane. The first four members have the trivial names methane (CH4), ethane (CH3CH3 or C2H6), propane (C3H8), and butane (C4H10). For the remainder of the alkanes, the first portion of the name is derived from the Greek prefix (see Table 11.4) that cites the number of carbons in the alkane followed by -ane with elision of the terminal -a from the prefix, as shown in Table 1.1. 

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The reaction with disubstituted formamides and phosphorus oxychloride, called the Vilsmeier or the Vilsmeier-Haack reaction,is the most common method for the formylation of aromatic rings. However, it is applicable only to active substrates, such as amines and phenols. An intramolecular version is also known.Aromatic hydrocarbons and heterocycles can also be formylated, but only if they are much more active than benzene (e.g., azulenes, ferrocenes). Though A-phenyl-A-methyl-formamide is a common reagent, other arylalkyl amides and dialkyl amides are also used. Phosgene (COCI2) has been used in place of POCI3. The reaction has also been carried out with other amides to give ketones (actually an example of 11-14),... 

Amination of Aromatic Hydrocarbons and Heterocyclic Analogs Thereof , WO patent 0069804, to Bayer, 2000. 

Warshawsky D, T Cody, M Radike, R Reilman, B Schumann, K LaDow, J Schneider (1995) Biotransformation of benzo[a]pyrene and other polycyclic aromatic hydrocarbons and heterocyclic analogues by several green algae and other algal species under gold and white light. Chem-Biol Interact 97 131-148. 

Monograph on the Evaluation of Carcinogenic Risks of the Chemical to Man Certain Polycyclic Aromatic Hydrocarbons and Heterocyclic Compounds", Internat. Agency Res. Cancer, World Health Organization, 1973 Vol. 3. 

Certain Polycyclic Aromatic Hydrocarbons and Heterocyclic Compounds, International Agency for Research on Cancer Monographs on the Evaluation of the Carcinogenic Risks to Humans LARC Lyon, France, 1972 Vol. 3. 

Arvin E, Jensen B, Aamand J, et al. 1988. The potential of free-living ground water bacteria to degrade aromatic hydrocarbons and heterocyclic compounds. Water Sci Technol 20(3) 109-118. 

The circulating electrons in the 7t-system of aromatic hydrocarbons and heterocycles generate a ring current and this in turn affects the chemical shifts of protons bonded to the periphery of the ring. This shift is usually greater (downfield from TMS) than that expected for the proton resonances of alkenes thus NMR spectroscopy can be used as a test for aromaticity . The chemical shift for the proton resonance of benzene is 7.2 ppm, whereas that of the C-1 proton of cyclohexene is 5.7 ppm, and the resonances of the protons of pyridine and pyrrole exhibit the chemical shifts shown in Box 1.12. 

Certain Polycyclic Aromatic Hydrocarbons and Heterocyclic Compounds... 

In our discussion of the Hammett correlation, we have confined ourselves mostly to benzene derivatives. Of course, a similar approach can be taken for other aromatic systems, such as for the derivatives of polycyclic aromatic hydrocarbons and heterocyclic aromatic compounds. For a discussion of such applications, we refer to... 

Recent Developments in Gas Chromatography and Spectroscopy of Polycyclic Aromatic Hydrocarbons and Heterocyclics H. D. Sauerland and M. Zander, ErdoelKohle, 1966, 19,502-505. 

The principal advances in the systematization of organic nomenclature have come from the International Union of Pure and Applied Chemistry (IUPAC) Commission on the Nomenclature of Organic Chemistry, and from the Chemical Abstracts Service. The IUPAC Definitive Rules for Hydrocarbons and Heterocyclic Systems (1957)4 and for Characteristic Groups (1965)5 have been widely accepted by the chemical community, and, in their latest revised form,6 constitute the standard reference work. These rules are closely related to those developed in parallel by Chemical Abstracts for indexing purposes, and it is fortunate that, as a result of close cooperation between the two bodies, there are few areas of disagreement. 

Zhang, L., Sannes, K., Shusterman, A.J., and Hansch, C., The structure-activity relationships of skin carcinogenicity of aromatic hydrocarbons and heterocycles, Chem. Biol. Interaction, 81, 149-180, 1992. 

The molecular orbital model vdiich has been developed to describe PES and UVA from aromatic hydrocarbons and heterocycles is a spectroscopically parameterized CNDO model, called the CND0/S3 model, constructed to describe these spectra for benzene (12), p-xylene (12), pyrolle (13), furan (14) and p-difluoroben-zene (15). The CNDO equations for the one electron orbitals are specified by Eqs. (lb)-(4b) in Lipari and Duke (1 ). The parameters utilized in these equations to define the CND0/S3 model are given in Table I. 

A list of common hydrocarbon and heterocyclic parent skeletons and their numbering appears in Table 4.1. 

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